input[type="checkbox"] {
    position: absolute;
    clip: rect(0, 0, 0, 0);
}

input[type="checkbox"]+label::before {
    content: '\2713';
    background: yellowgreen;
    display: inline-block;
    vertical-align: .2em;
    width: .8em;
    height: .8em;
    margin-right: .2em;
    border-radius: .2em;
    background: silver;
    text-indent: .15em;
    line-height: .3;
}

input[type="checkbox"]:focus+label::before {
    box-shadow: 0 0 .1em .1em #58a;
    content: '\2713';
}

input[type="checkbox"]:disabled+label::before {
    background: gray;
    box-shadow: none;
    color: #555;
}



/* input[type="checkbox"] {
    position: absolute;
    clip: rect(0, 0, 0, 0);
}

input[type="checkbox"]+label {
    display: inline-block;
    padding: .3em .5em;
    background: #ccc;
    background-image: linear-gradient(#ddd, #bbb);
    border: 1px solid rgba(0, 0, 0, .2);
    border-radius: .3em;
    box-shadow: 0 1px white inset;
    text-align: center;
    text-shadow: 0 1px 1px white;
}

input[type="checkbox"]:checked+label,
input[type="checkbox"]:active+label {
    box-shadow: .05em .1em .2em rgba(0, 0, 0, .6) inset;
    border-color: rgba(0, 0, 0, .3);
    background: #bbb;
} */